16alpha, 17alpha-cyclophosphate and 16alpha, 17alpha-cyclophosphonate esters of 16alpha, 17alpha-dihydroxy steroids



United States Patent 0 This invention relates to 16a,l7x-cyclophosphate and 16a,l7a-cyclophosphonate esters of 16a,17adihydroxy steroids of C-ring substituted pregnenes, that is steroids having a pregnene, pregnadiene or pregnatriene nucleus. More particularly, the invention relates to compounds represented by the formula In Formula I, the 1,2- and/or 6,7-positions may be saturated or double bonded so that A A A and A -pregnanes are included within the scope of this invention.

The symbols in formula have the following meanings: R represents hydrogen, R represents fi-hydroxy or together R and R are keto (L O); R represents hydrogen, halogen or lower alkyl; R represents a hydrocarbon radical of less than 10 carbon atoms; X and X each represents hydrogen or halogen, but at least one of these two symbols represents hydrogen; Y represents hydrogen or lower alkyl, preferably methyl; Z represents hydrogen, halogen, hydroxy or the acyloxy radical of a hydrocarbon carboxylic acidof less than 10 carbon atoms and n represents either 0 or 1.

The symbols R", X, X" and Z represent all four halogens but chlorine and fluorine are preferred in this group. The same or different halogens may appear in a given compound. Lower alkyl groups represented by Y and R" include traight and branched chain saturated alkanoic acids, preferably lower alkanoic acids such as acetic, propionic, butyric, hexanoic acids and the like, lower alkenoic acids such as acrylic acid, monocyclic aromatic carboxylic acids such as benzoic and 0-, mand ptoluic acids, cycloalkanoic acids such'as cyclohexanoic acid, cycloalkenoic acids such as cyclohexenoic acid, and monocyclic aryl-lower alkanoic acids such as phenylacetic and fi-phenylpropionic acids.

phonate esters e.g. cyclophenylphosp'honate, cyclophenylphosphate, cyclomethylphosphate, cyclobenzylphosphate 3,%9,439 Patented Dec. 18, 1962 ICC and cyclobenzylphosphonate, of the following C-ring substituted-16a,17a-dihydroxypregnenes are compounds of this invention. They and the working examples which follow serve to illustrate the class of esters included.

16a-hydroxyhydrocortisone, l6a-hydroxyhydrocortisone 21-acetate, Zwmethyl-16a-hydroxyhydrocortisone, 9afluoro-l6whydroxyhydrocortisone, 12a chloro-l6a-hydroxyhydrocortisone, oa-methyh1oa-hydroxyhydrocortisone, 6a-fiuoro16a-hydroxyhydrocortisone, 6a,9a difluoro-l6m-hydroxyhydrocortisone, 9a,21-difluoro-A -pregnene-1l5,l6a,17a-triol 3,20-dione.

l6a-hydroxycortisone, 16oc-hYCl1'OXYCOIfiSOl16: ZI-acetate, Za-methyl-16a-hydroxycortisone, 9a-fluoro-l6a-hydroxycortisone, 12a-fiuoro-16a-hydroxycortisone, 6a-methyl- 16mhydroxycortIsone, 6oz chloro-16a-hydro-xycortisone, 6a,9a-difiuoro-16a-hydroxycortisone, 90,21 difluoro-M- pregnene l 6u,17oc-dl01-3, 1 1,20-trione.

16a-hydroxyprednisolone, 9a-fluoro-IGe-hydroXyprednisolone, 12x-chloro-16u-hydroxyprednisolone, 6a-methyl-l6x-hydroxyprednisolone, 6a-fluoro-16a-hydroxyprednisolone, afia-difluorO-l6ahydroxyprednisolone, 9a, 21-diiluorO-A -pregnadiene-l 1fl-160c,l7wtriOl-3,20-di0116.

16zx-hYd1OXYpI6dI1lSOH3, l6a-hydroxyprednisone 21- acetate, ot-iluoro 16cc hydroxyprcdnisone, Bar-fluoro- 16a-1ydroxyprednisone, 6arnethyl l6a-hydroxyprednisone, 6ot-chloro-1oa-hydroxyprednisone, 60:,9oc-dlfltl0l0- 16oc-hydroxyprcdnisone.

9a-fluoro-A -pregnene-115,16a,l7ot-triol-3,20-dione, 9afiuoro-A -pregnadiene-16a,17ot-diol 3,11,20 trione, 2ifiuoro-M-pregnene-l l,8,l6a,17u-triol 3,20 dione, 12oziluoroA -pregnene,11fl,l6a,17u-triol-3,20 dione, 6zz-methyl-9u-chloro-A -pregnene-11,8,16rx,17u-triol-3,20-dione, 6a, 9oz-difluoro-A -pregnene-llB,l6u,17a-triol-3,20 dione, 90c- 21-difiuoro-A -pregnatriene 11[5',160a,17o.' Biol-3,20- d-ione, 12a fluoro-A '-pregnatriene-1lfl,l6u,17a-triol-3, ZO-dione.

The compounds of this invention can be prepared by reacting a compound of the formula ria z R a e o GE-I wherein the 1,2- and/or 6,7-positions are saturated or double bonded, R, R, R, X, X, and Y have the same meaning as before and Z represents hydrogen, halogen or the acyloxy radical of a hydrocarbon carboxylic acid of less than 10 carbon atoms, with a dihalide of the formula Hal\ g are} -a' n Hal wherein R and n have the meaning defined above and Hal represents a halogen, preferably chlorine.

Such dihalides include, for example, phenylphosphonyl (III) dichloride, benzyl-phosphonyl dichloride, phenylphosphoryl dichloride, methylphosphoryl dichloride and the like. The reaction is carried out in the presence of an organic nitrogen base such as pyridine, collidine, triethanolamine, quinoline or the like and the product is recovered from the solution by conventional procedures. Preferably the compound of Formula II is dissolved or suspended in the basic medium and. then treated with an equimolar proportion or excess of the dihalide at a temperature below or about C.

The starting materials of Formula I are known substances or are readily obtained from known compounds. Thus l6a,l7ot-dihydroxy compounds may be obtained from their known l7a-hydroxy analogs by enzymatic hydr'oxylation at the l6-position by means of the microorganism Strepromyces roseochromogenus according to the method described in US. Patent No. 2,855,343. Similarly, compounds saturated in the 1,2-position may be converted to the corresponding 1,2-unsaturated compound by the action of Bacterium cyclooxydans according to the method described in Example 1 of US. Patent No. 2,- 822,318.

tlompounds of Formula II bearing IZa-halo and/ or 6&- methyl substituents may be produced as described in my co-pending application Serial No. 677,205, filed August 9, 1957 and now abandoned.

The 2l-acyloxy-i6a,17ot-diol starting materials for the compounds of this invention can be obtained by treating the corresponding l6ct,17a,2l-triols with an acid anhydride in pyridine and separating the resulting mixture by fractional crystallization. An alternate, more lengthy but more general procedure involves the treatment of the l6ot,i7a,2l-triol with a ketone (eg. acetone) or the aldehyde in the presence of an acid catalyst (e.g. perchloric acid) to yield the corresponding l6ot,l7 x-ketal or acetal which is then treated with an acyl chloride (e.g. acetyl chloride) or an acid anhydride (e.g. acetic anhydride) in a basic organic medium (e.g. pyridine) to form the corresponding 2l-acyloxy-l6ct,l7a-ketal or acetal. The latter is converted by hydrolysis with aqueous formic acid to the desired 2l-acyloxy-l6ot,i7a-diol by the procedure described in my copending application Serial No. 84,989, filed January 26, 1961.

The 21-l1alo-l6tt,l7t .-diol starting materials for the compounds of this invention are prepared by converting the corresponding l6ot,l7 x,2l-triol to its l6ot-l7ot-ketal or acetal as described above, treating the latter with an organic sulfonyi chloride (eg. tosyl chloride or mesyl chloride) to prepare the 2l-sulfonyloxy derivative which is then ZI-halogenated by treatment with an alkali metal halide (e.g. potassium bifiuoride, lithium chloride, lithium bromide and sodium iodide). The latter is converted to the desired 21-halo-16ot,l7ot-diol compound by hydrolyzing ofi" the 16a,l7wacetal or ketal grouping with formic acid.

When a 6,7-saturated steroid is used as the starting material and a 6-dehydrofinal product is desired, the latter may be obtained by treating the 6,7-saturated-l6al7acyclic esters of this invention with a dehydrogenating agent capable of selectively dehydrogenating this position. A suitable dehydrogenating agent is chloranil in ethyl acetate and acetic acid.

Among the starting materials of Formula II which may be used to produce the products of Formula I are the following:

The Zl-esters of 16orhydroxyhydrocortisones, such as the ZI-acetates of lSa-hydroxyhydrocortisone, Zinc-methyl- 16a-hydroxyhydrocortisone, 9a-fluorol6a-hydroxyhydrocortisone, lZa-chloro-l6a-hydroxyhydrocortisone, 6amethyl 16a hydroxyhydrocortisone, 60 fluoro 16ahydroxyhydrocortisone, and 6a,9a-difiuoro-l6a-hydroxyhydrocortisone.

The Zl-esters of hydroxycortisones such as the 21-acetates of l6ct-hydroxycortisone,

2ot-rnethyll 6a-hydroxycortisone, 9a-fiuOrO-l 6a-hydroxycortisone, i2tt-fiuorol 6ot-hydroxycortisone, GQt-rnethyl-l 6ot-hydroxycortisone, 6a-chlorol Ga-hydroxycortisone, Gee-11110104 6a-hydroxycortisone, and 6a,9ct-difluorol 6a-hydroxycortisone.

The 21-esters of l6a-hydroxyprednisolones such as the 21 acetates of 16 a-hydroxyprednisolone,

9ot-fiuorol 6a-hydroxyprednisolone, t-Ch10101 6u-hydroxyprednisolone, 6a-methyll 6ot-hydroxyprednisolone, 6ct-fluoro-l 6a-hydroxyprednis olone, 6LX,9Q.-dlflLlOIO-16Dt-hYdI'C-XYPI'6dDlSOlOHE.

The 2l-esters of l6ot-hydroxyprednisones such as the 2l-acetates of l6ot-hydroxyprednisone,

9a-flu orol 6ot-hydroxyprednisone, l2ot-fluorol 6ot-hydroxyprednisone, 6ot-methyll 6tt-hydroxyprednisone, 6a-chlorol 6u-hydroxyprednisone,

6 afie-difiuorol Gwhydroxyprednisone.

ll-hydroxyor l1-keto-A -pregnene-16a,l7a-diol 3,20- diones such as The compounds of this invention are physiologicair, active substances which possess glucocorticoid and antrinflammatory activities and hence can be used in lieu of known glucocorticoids such as hydrocortisone and cortisone in the treatment of rheumatoid arthritis for which purpose they can be administered in the same manner as, for example, hydrocortisone, the dosage being adjusted for the relative potency of the particular steroid. They may be administered orally, for example, in the form of tablets or capsules by incorporating a therapeutic dosage with a carrier according to conventional practice.

The following examples are presented to more fully illustrate the present invention (all temperatures being expressed in degrees centigrade).

EXAMPLE 1 Triamcinolone 16a,]7a-Cyclophenylph0sph0nate 21- Acetate M12... 238 M 3 ml??? 5.75, 5.82, 6.04, 6.20 and 625p.

Analysis.-Calcd for C H O F (436.46): C, 63.29; H, 6.69. Found: C, 63.21; H, 6.81.

B. Preparation of triamcinolone 16a,17ot-cycl0phenylphosphonate 21-acetate.To a solution of 1 g. of triamcinolone 2l-monoacetate in 30 ml. of pyridine is added with stirring at 15, 2 m1. of phenylphosphonyl dichloride. The reaction is allowed to proceed at l5 for 2.88 (shoulder), 2.98,

2.5 minutes after which time ice water is added. Chloroform is added to the mixture and the layers are separated. 'Ihe chloroform extract is washed with water, 1 N sulfuric acid, water, dilut sodium bicarbonate solution and again with water, dried over sodium sulfate and the solvent removed in vacuo. The resulting residue (about 1.2 g.) is dissolved in ml. of chloroform and 50 ml. of benzene and chromatographed on 20 g. of neutral alumina. Elution of the column with 500 ml. of a mixture of one part of chloroform and 5 parts of benzene yields about 560 mg. of crystalline material, which after recrystallization from acetone-hexane represents analytically pure tria-mcinolone 16a,17a-cyclophenylphosphonate 21- acetate possessing the following properties: M.P. 288- 289"; [M +130 (c., 1.12 in chlf.);

Analysis.-Calcd for C H O SF (482.50): C, 57.24; H, 5.64; S, 6.65. Found: C, 57.60; H, 5.68; S, 6.32

EXAMPLE 2 T rz'amcinolone 1611,] 7u-Cyci'0phenylphosphonate To a solution of 100 mg. of triamcinolone 160:,17acyclophenylphosphonate 21-acetate in 10 ml. of methanol is added under nitrogen 1 ml. of a 10% solution of potassium carbonate in water. The mixture is allowed to stand at room temperature for hour after which the mixture is acidified with 0.1 ml. of glacial acetic acid, 2 ml. water are added and the methanol removed in vacuo. The resulting crystalline precipitate is filtered ofif, washed with water and dried to yield the product triamcinolone 16a,17ot-cyclophenylphosphonate.

EXAMPLE 3 Triamcinolone 1 6 0a,] 70c-C yclo ph enyl phosphate 2] Acetate To a solution of 100 mg. of triamcinolone ZI-acetate in 3 m1. of pyridine is added at With stirring 0.1 ml. of phenylphosphoryl dichloride. The reaction is allowed to proceed at -15 for 15 minutes, after which time ice water is added and the mixture extracted with chloroform. The chloroform extract is washed with water, 1 N sulfuric acid, water, dilute sodium bicarbonate, again with water, dried over sodium sulfate and the chloroform removed in vacuo. The resulting residue constitutes triamcinolone- 16a,17u-cyclophenylphosphate ZI-acetate after recrystallization from 95% alcohol.

EXAMPLE 4 6-Dehydr0triamcin0l0ne 16a,]7ot-Cyclophenylphosphonate 21 Acetate A solution of 250 mg. of the product of Example 1B and 1.250 g. of recrystallized chloranil in 15 ml. of tert. butanol is heated under reflux for three hours. The mixture is cooled, filtered, the filtrate poured into water and the layers separated. After an additional extraction of the aqueous layer with ethyl acetate, the ethyl acetate extract is washed With a 1 N sodium hydroxide solution until the aqueous layer becomes colorless. The washed extract is dried over sodium sulfate and evaporated to dryness in vacuo leaving as residue the product 6-dehydrotriamcinolone 16a,17a-cyclophenylphosphonate 2l-acetate.

EXAMPLE 5 To a solution of 1 g. of triamcinolone acetonide in 10 ml. of anhydrous pyridine is added at 0 1 ml. of methanesulfonyl chloride. After two hours at 0, ice water is added and the precipitated mesylate is removed by filtration. The precipitate is washed thoroughly with water and dried in vacuo, then recrystallized from acetonehexane. The triarncinolone acetonide 21-mesylate melts at about 248-250 (dec.) or 286-287 (dec.) (polymorphic forms).

A mixture containing 1 g. of triamcinolone acetonide 21-mesylate, 1 g. of potassium fluoride and 25 ml. of ethylene glycol is refluxed (180) for 19 hours. The dark solution is poured into ice water and extracted with chloroform. The chloroform extract is washed with water, dried over sodium sulfate and evaporated to dryness in vacuo. The residue, 16a,17a-isopropylidene-9a,2l-difluoro-A -pregnad-iene-11,8,l6ot,17a-triol-3,20-dione, is recrystallized from acetone with the aid of charcoal and melts at about 310.

The above product is deacetonated by treatment with formic acid by the procedure of Example 7 of my copending application Serial No. 84,989, filed January 26, 1961, to obtain 9a,21-difluoro-A pregnadiene-11/3,16ot,17atriol-3,20-dione.

Treatment of the above products with phenylphosphonyl dichloride in pyridine at -l5 for 2.5 minutes in accordance with the procedure of Example 1B yields the final product 900,21-difluOro-A -pregnadiene-l1fi,l6a,17oztriol-3,20-dione 16a,17a-cyclophenylphosphonate.

EXAMPLE 6 A solution of 200 mg. of triamcinolone acetonide 21- mesylate and 900 mg. of lithium chloride in 25 ml. of dimethylformamide is kept at for 24 hours. The mixture is poured on ice, extracted with chloroform and the chloroform extract Washed with Water and dried over sodium sulfate. Evaporation of the solvent in vacuo yields 21-chloro-9ot-luoro-A -pregnadiene-11,8,16a,17vrtriol-3,20-dione 16,17-acetonide which melts at about 310 after recrystallization from acetoneethanol.

By further processing the above product as described in Example 3, 21-chloro-9a-iluoro-d -pregnadiene-11p, :,17oc triol 3,20 dione 1605,17Ci cyclophenylphosphate is obtained.

EXAMPLE 7 6ot-Flu0r0triamcinolone J 6 11,1 7 Ot-C yclomezhylphosphate 21 -Pr0pi0nae A. Preparation 0] 6a-fiuor0lrianzcinOIone 21-pr0pi0- nate.-A solution of 200 mg. of ot-fiuorotriamcinolone acetonide in 1 ml. of pyridine and 0.5 m1. of propionic anhydride is allowed to remain at room temperature for twenty hours. After removal of the reagents in vacuo the residue 16a,l7a-acetonide of 6ot-fluorotriamcinolone 21-propionate is deactonated with 60% formic acid at 100 according to the procedure described in Example 5, thereby yielding 6a-fiuorotriarncinolone 21-propionate.

B. Preparation of oa-fluorotriamcinalone cyclomethyiphosphate Z1-pr0pz0nate.To a solution of 1 g. of the product of part A in 30 m1. of pyridine is added, with stirring, at 15, 2 ml. of methylphosphoryl dichloride. The reaction mixture is treated as in Example 113 to yield the product 6ot-fiuorotriamcinolone 16u,17a-cyclomethylphosphate 2l-propionate.

EXAMPLE 8 6 a-F'luorotriamcinolone 1 6 (1,] 7 a-Cyclopheny l phosphate 21-Pr0pi0nate To a solution of 100 mg. of 6a-fluorotriamcinolone- 2l-propionate in 3 m1. of pyridine is added at -15 with stirring 0.1 ml. of phenylphosphonyl dichloride. The reaction is allowed to proceed at 15 with stirring for 15 minutes, after which time ice Water is added and the mixture extracted with chloroform. The extract is washed with water, 1 N sulfuric acid, water, dilute sodium bicarbonate, again with water, dried over sodium sulfate and the chloroform removed in vacuo. The residue is recrystallized from 95% alcohol to obtain the product, 6a-fluorotriamcinolone 16a,17w-cyclobenzylphosphonate 21-propionate.

7 EXAMPLE 9 Za-Methy ltriamcinolone 160e,] 7ot-Cycl0benzy [phosphate 2 I -A cetate 200 mg. of 2a-methyl-triamcinolone 21-acetate (prepared by sequentially acetonating, acetylating and deacetonating 2a-methyl triamcinolone in accordance with the procedure of Example 7A) is dissolved in 3 ml. of pyridine and treated at with stirring with 2 ml. of benzylphosphoryl dichloride in accordance'with the procedure of Example 1B thereby yielding the product methyltriamcinolone 16a,17a cyclobenzylphosphate 21-acetate.

EXAMPLE 10 2 u-Methyl-l 6 oc-H y droxyhydrocortisone 1 6 00,] 7a- Cyclophenylphosphonate 21-Acetate Zoc-mfithYl-lGoc-hYdIOXyhYClTOCOItlSOIIG 21-acetate (prepared by sequentially acetonating, acylating and deacetonating 2u-methyl-16a-hydroxyhydrocortiscne in accordance with the procedure in Example 7A) is treated in a solution of pyridine with phenylphosphonyl dichloride as described in Example 13 thereby yielding the product 2u-methyl-l6a-hydroxyhydrocortisone 1604,17a-CYC10- phenylophosphonate 21-acetate.

EXAMPLE 1 1 Zoe-M ethyl-1 6 Ot-H ydroxyhydrocortisone 16a,17 x- Cyclophenylphosphate 2 1 -A cetate Following the procedure of Example 3, 2a-methyl-16ahydroxycortisone ZI-acetate in pyridine is treated with phenylphosphoryl dichloride. The reaction yields the product ZOL-HIfithYl-160L-hydIOXyCOrtiSOI16 16cc,17oc-CyCl0- phenylphosphate 21-acetate.

EXAMPLE 12 Zu-Methyl-6-Dehydr0-1ou-Hydroxyhydrocortisone 1 6w] 7a-Cycl0phenylphosphate 21-Acetare The product of the preceding example is treated with recrystallized chloranil in accordance with the procedure of Example 4 yielding the product 2ix-methyl-6-dehydro- 16a hydroxyhydrocortisone 1604,17 cyclophenylphosphate ZI-acetate.

EXAMPLE 13 I2m-Chl0r0-1 6a-Hydr0xyc0rtis0ne-1 6 0a,] 7OL-CyClU- phenylphosphate 21-A cetate Substitution of 1 g. of 12a-chloro-1Got-hydroxycortisone-Zl-acetate (prepared by sequentially treating 120cchloro16u-hydroxycortisone with acetone and perchloric acid, acetic anhydride and pyridine and 60% formic acid in accordance with the procedure of Example 7A) is treated wtih phenylphosphonyl dichloride in accordance with the procedure of Example 1B thereby yielding the product 12m-chloro-16a-hydroxycortisone 16oz, 17ot-cyclophenylphosphonate 21-acetate.

The corresponding free 21-01 is obtained by hydrolysis of the 21-acetate with a solution of potassium carbonate.

EXAMPLE 14 J Zoe-ChlOrO-I 6 Ot-H ydroxycortisone 160 7a-Cy clobenzyl hosph onate 21 -A cetate To a solution of 100 mg. of 12a-ChlO1'0-160L-hYdI'OXycortisone 21-acetate in 3 ml. of pyridine is added at 15 with stirring 0.1 ml. of benzylphosphonyl dichloride. The reaction is allowed to proceed at 15 for 15 minutes after which time ice water is added and the mixture extracted with chloroform. The chloroform extract is washed with water, 1 N sulfuric acid, water, dilute sodium bicarbonate, again with water, dried over sodium sulfate and the chloroform removed in vacuo. The resulting residue after recrystallization from 95% alcohol yields the product, 12a-chloro-16a-hydroxycortisone 16a,17ot-cyclobenzylphosphonate 21-acetate.

8 EXAMPLE 1s A IZa-ChIOrO-I 6 oc-H ydroxycortisone a,] 7u-Cycl0- benzylphosphonate 21 Acetate and the 1,2- and 6,7-unsaturates thereof, wherein R represents hydrogen, R represents fi-hydroxy and together R and R are keto; R" represents a member of the group consisting of hydrogen, chlorine, fluorine and lower alkyl; R represents a hydrocarbon radical of less than 10 carbon atoms; X and X each represents a member of the group consisting of hydrogen, chlorine and fluorine, at least one representing hydrogen; Y represents a member of the group consisting of hydrogen and lower alkyl; Z represents a member of the group consisting of hydrogen, chlorine, fluorine, hydroxy and the acyloxy radical of a hydrocarbon carhoxylic acid of less than 10 carbon atoms; and n represents an integer from 0 to 1.

2. A compound of the formula (EH 6 acyl halo wherein the acyloxy group is the acyloxy radical of a hydrocarbon carboxylic acid of less than 10 carbon atoms and the halo group is a member of the group consisting of chlorine and fluorine.

3. A compound of the formula CH 0 acyl l 2 0 (=0 2! Ig P-1ower alky halo wherein the acyloxy group is the acyloxy radical of a hydrocarbon carboxylic acid of less than 10 carbon atoms and the halo group is a member of the group consisting of chlorine and fluorine.

4. A compound of the formula wherein the acyloxy group is the acyloxy radical of a hydrocarbon carboxylic acid of less than carbon atoms and the halo group is a member of the group consisting of chlorine and fluorine.

5. A compound of the formula fit-I 0 acyl 8. 9a-fluoro-16a-hydroxyhydrocortisone l6u,l7a-cyclophenylphosphonate ZI-acetate.

9. 9a,2ldifluoro-A -pregnadiene-11fi,16a,17a-triol- 3, ZO-dione 16cc, 1 7a-cyclophenylphosphonate.

10. 6a-fiuorotriamcinolone 16a,17a-cyclomethylphosphate 2l-propionate.

11. The process for the preparation of the compounds of claim 1' which comprises treating a member selected from the group consisting of compounds of the formula:

(I!H Z' ll Ha1 mlnwherein R and n are as defined in claim 1 and Hal represents halogen.

No references cited, 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF STEROIDS OF THE FORMULA 